It is conventional practice to provide a closet flange at the location of each water closet to be installed in a home, building or the like. The closet flange has a cylindrical body portion which extends through an opening in the floor and a surrounding flange at its inlet end which overlies the floor and is affixed thereto. The water closet, when installed, is mounted on the closet flange and is bolted thereto. The closet flange not only serves as a mounting means for the water closet, but it also connects the water closet to the plumbing leading to the soil pipe and vent pipe assembly, all as is well known in the art.
In the plumbing industry today, it is common to make piping such as soil pipe and the like, and fittings such as elbows, closet flanges, standard threaded plumbing plugs and the like of plastic material such as acrylonithile-butadiens-styrene (ABS) or polyvinylchloride (PVC). While the teachings of the present invention are equally applicable to metallic pipe and pipe fittings, for purposes of an exemplary showing, the invention will be illustrated in its application to plastic closet flanges to be used with plastic fittings and soil pipe.
During plumbing construction it is frequently desirable or required to perform an air test or a water test to assure that the various joints and the like are properly connected and sealed. According to prior art practices, various types of plug means were attached directly to the soil pipe to seal the pipe for purposes of such testing, prior to the installation of the closet flange. Although relatively low pressures are used in such testing, the various plug means used were frequently subject to "blow-out," requiring resealing and retesting.
Prior art workers have developed a closet flange with a knock-out closure member at its inlet end, the closure member constituting an integral, one-piece part of the molded plastic closet flange. This integral closure member not only closes the inlet end of the closet flange, but also enables water and air tests to be conducted with the closet flange in place. However, when a water closet is to be mounted on the closet flange, the integral knock-out closure member is removed by an appropriate blow or blows of a suitable tool such as a hammer. Frequently, the knock-out closure member, once broken away, falls down into the plumbing, sometimes resulting in a removal problem.
The present invention is based upon the discovery that if the entrance end of an otherwise conventional molded plastic closet flange is modified so as to be provided with a series of standard plumbing threads, it can temporarily be closed and sealed by means of a standard 3" or 4" screw plug. Such screw plugs are well-known in the art, and are most commonly available in 3" and 4" diameters. The closet flange can be so sized as to accommodate a 3" or a 4" standard plumbing plug.
The improved closet flange of the present invention has been found to provide a number of advantages. First of all, the plumbing can be completed up to and including installation of the closet flange and the closet flange can be easily closed until such time as a water closet is installed thereon. The use of a conventional screw plug enables sealing of the system for purposes of air or water testing. The plug provides an essentially fail-safe seal. Furthermore, for test purposes, a conventional screw-base air or water test gage can be threadedly engaged in the closet flange, making an adequate seal. Finally, the interior configuration of the entrance end of the closet flange, including the threads, enables the use of a horned wax ring, if desired. This will be illustrated hereinafter.